The invention relates to a delay line for travelling-wave tubes, comprising a hollow guide provided with successive transverse discs formed from a ductile material, which discs have at least one central opening for the passage of the electron beam and provided with respective attenuation members which extend into the hollow guide interior and have their longitudinal axes extending at least approximately parallel to the longitudinal axes of the delay line. The respective attenuation members are each mechanically rigidly mounted in a cooperable recess formed in the associated transverse disc. The invention also relates to a method for producing a delay line of this type.
A delay structure of the general type referred to is known from German Pat. No. 23 47 209, corresponding to U.S. Pat. No. 3,924,151, with the construction therein disclosed utilizing cylindrical attenuation members which are soldered into the transverse walls, each of which is additionally provided with a coupling opening or slot therein. While attenuation cylinders secured by a soldering operation are rigidly mounted in the desired operative positions, as has become apparent, completely exact reproducible attenuation values cannot be achieved as the solder spreads out during the soldering operation, in particular, on the metallized areas of the attenuation cylinder involved, and thus operatively loads the individual cells to an extent that is not completely controllable.